However,it is very difficult to measure the Ge-center ESR signal in laboratory because it is very weak.
Al-center can attenuate 20 percent after 2 hours sunlight bleaching and after tens to hundreds of hours bleaching it still maintains a stable residual signal,50-80 percent.
The remnant signals are not equal under different sediment environment.
We usually gain a bigger age using Al-center ESR signal for the uncertain remnant.
The dose rate is found from the summation of the concentrations of radioactive materials in the sample (internal dose rate) and its surrounding environment (external dose rate).